All consecutive patients who had coronary angiography at the Luzerner Kantonsspital between July 1st 1996 and July 31st 2008 and who had no significant coronary stenoses (no coronary stenoses ≥ 50%) were recruited for this study. Patients are extensively examined during angiography using acetylcholine infusion and fast atrial pacing. According to the result of the additional invasive examination (vasospasm, vasoconstriction, vasodilation; symptoms during examination) a distinct diagnosis is attributed to the patients (small vessel disease, vasospastic disease, hypertensive heart disease, rhythm disorder, or extracardiac thoracic pain including pulmonary hypertension). Patients are followed-up after 10 years and prognosis of these patients is assessed (including mortality, cardiovascular events, re-angiography, functional status after 10 years).